Hardened closure-system for underground structures

ABSTRACT

THIS INVENTION RELATES TO A ROTATING SPHERICAL SHELL DOOR FOR HARDENED UNDERGROUND STRUCTURES. IT PROVIDES FOR DEBRIS REMOVAL BY EXPLOSIVE PROPULSION OF A CAP ON THE SPHERE AND COLLECTION OF ANY DEBRIS FALL BACK INSIDE THE SHELL. THE SHELL CAN THEN BE ROTATED FOR EGRESS OR INGRESS THROUGH A CYLINDER IN THE SPHERICAL STRUCTURE.

Feb. 16, 1971 0,1, PRICKETT ETAL 3,562,953

HARDENED CLOSURE SYSTEM FOR UNDERGROUND STRUCTURES Filed Feb. 5, 1968 2 Sheets-Sheet 1 Feb. 16, 1971 PRICKETT ETAL 3,562,953

HARDENED CLOSURE SYSTEM FOR UNDERGROUND STRUCTURES Filed Feb. 5, 195B 2 Sheets-Sheet 2 United States Patent Office Patented Feb. 16, 1971 ABSTRACT OF THE DISCLOSURE This invention relates to a rotating spherical shell door for hardened underground structures. 'It provides for debris removal by explosive propulsion of a cap on the sphere and collection of any debris fall back inside the shell. The shell can then be rotated for egress or ingress through a cylinder in the spherical structure.

BRIEF SUMMARY This invention provides an unique process of hardening closures for underground structures such as missile silos and shelters and provides a process of removing overburden rapidly that might be created by the lip of a crater from a nuclear explosion, ice and snow or other debris. The invention allows ready access to the underground structure when desired.

The basic element of the system consists of a rotating steel sphere which has an open cylinder through its center. When the silo or shelter is closed the open cylinder is in the horizontal position so that the silo or shelter beneath the sphere is completely protected from outside pressures. The sphere may be made strong enough to withstand extremely high pressures (thousands of p.s.i.). When it is desired to have access to the underground structure the sphere is rotated 90 degrees so that the cylinder forms an opening to the underground structure. The rotating sphere incorporates a high internal pressure, a debris reservoir and an explosively separable cap, the combination of which allows for the removal of debris from the top of the closure prior to opening.

The sphere is embedded in a spherical steel shell in reinforced concrete or similar material. The area between the shell of the rotating sphere and the shell of the open cylinder is hollow and may be pressurized to any desired level. For spheres to be used as closures for hardened structures where it may be necessary to remove overburden or debris before opening, the top or cap of the sphere will be released explosively. The internal pressure within the sphere assists in ejecting the released portion of the sphere carrying any overburden or debris with it. Any residual debris that may fall back will be caught and contained within the hollow portion of the sphere. The sphere will then be rotated 90 degrees to the open position by means of motor driven gear trains or mechanical linkages.

When the rotating sphere is in the closed position the opening will be sealed from any outside pressure by means of a wedged ring pressure seal which will fit over the joint between the rotating sphere and the reinforced concrete base. High overpressures from the outside will force this wedge into the space between the rotating sphere and the reinforced concrete to insure a positive seal. This wedged ring will be explosively released and ejected with the spherical cap. For other applications for the rotating closure where it is not necessary to remove overburden the separable cap feature need not be used.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a cutaway view of the rotating sphere over a missile silo embedded in a reinforced concrete structure. The open cylinder through the center of the sphere is in the horizontal or closed position. FIG. 2 shows the sphere with the cylinder in the vertical position to permit egress and ingress to the buried structure.

DETAILED DESCRIPTION FIG. 1 shows the basic concept and design of the spherical rotating closure. Detail 1 of FIG. 1 is the outer shell of the sphere. 2 is the steel lined reinforced concrete base for the closure mechanism and the underground structure. 3 is the steel shell of the access cylinder. The conical shaft bearings around which the sphere rotates are labeled 4. 5, FIG. 2, is the rotating mechanism. 6 is the wedged ring pressure seal which is forced downward to form a positive seal when overpressure is applied from the top. such as from a nuclear explosion. The pressure seal will be removed with the top cap 7 of the basic sphere when it is explosively ejected. 8 is a ring of primacord or other explosive to cut the sphere and allow the cap of the sphere to be released. 9 is the space between the outer shell of the sphere and the walls of the access cylinder. This volume is pressurized to assist in ejecting the cap of the sphere when explosively cut, carrying the overburden or debris and the pressure seal with it. Additional ejection forces may be provided to help lift the cap and overburden on applications where excessive overburden is predicted. 10 is a ring gear attached to the equatorial plane of the sphere which is driven through standard gear reduction boxes and motors. The motor-gear system rotates the spherical shell around the conical axles 4. 11 is the missile silo or the opening of an underground structure. 12 is a Teflon or a similar sealant-lubricant which acts as a seating material when outside pressure is applied to the sphere to distribute the applied forces on the sphere over the entire spherical bearing surfaces as well as to the conical axles. This sealant also serves as a filter to prevent foreign material from entering the space between the rotating sphere and its base and as a wiper during rotation.

FIG. 2 shows the sphere rotated so that the access cylinder is in the vertical position for missile launch or to permit other egress and ingress to the buried structure.

What is claimed is:

1. In an underground structure for missiles or the like having an opening therein adjacent the ground level, the improvement comprising; a hollow sphere mounted in said opening for rotation about a horizontal axis, said sphere having a cylinder extending therethrou'gh on an axis normal to said horizontal rotation axis defining a cylindrical opening to said underground structure, means for rotating said closure from an open position aligning said cylindrical opening with the opening in the underground structure to a closed position at right angles thereto, the hollow sphere containing a high internal pressure,

4 an explosively separable cap on said sphere facing out- References Cited wardly when the closure is in the closed position, whereby UNITED STATES PATENTS the combination of the explosively separated cap and the 2 081 316 5/1937 Wilkinson ct P e P e 5 3,135,163 6/1964 Mechlin, Jr., et a1. 89- 1817 of the sphere actln-g as a reservoir for debris WhlCh falls back on the closure after separation of the cap, the sphere KENNETH DOWNEY, Primary Examiner belng surmounted by a wedge-shaped compression ring which protects the underground structure from external X- shock when the closure is in the closed position. 10 89 1-817 

